Urs Hölzle, Google's SVP for Operations, responds to a Sunday Times article that cites a Harvard study claiming that two Google searches "can generate about the same amount of carbon dioxide as boiling a kettle for a cup of tea."

Not so, says Hölzle. The reported energy consumption is "many times too high," he says, in part because Google searches are so fast that the hardware doesn't have to work very long on a given query.

Nick Carr was dubious about the reported numbers, but says it's useful in any case to be reminded of the high cost of data centers. And he points out that Google works at cross purposes -- it wants to be efficient, but it also makes more money when people do more searches.

UPDATE: Harvard Physicist Sets Record Straight on Internet Carbon Study

"For some reason, in their story on the study, the Times had an ax to grind with Google," Wissner-Gross told TechNewsWorld. "Our work has nothing to do with Google. Our focus was exclusively on the Web overall, and we found that it takes on average about 20 milligrams of CO2 per second to visit a Web site."

And the example involving tea kettles? "They did that. I have no idea where they got those statistics," Wissner-Gross said.